Automatic test equipment (ATE) refers to an automated, usually computer-driven, apparatus for testing devices, such as semiconductors, electronic circuits, and printed circuit board assemblies. A device tested by ATE is referred to as a device under test (DUT).
A pin electronics driver in ATE configures signal pins to output voltages to the DUT and to receive voltages from the DUT. Implementing a pin electronics driver using complementary metal oxide semiconductor (CMOS) technology can be advantageous because it results in less power consumption by the ATE. In more detail, CMOS technology uses both N-channel and P-channel transistors. During operation of a CMOS device, only one of the two types of transistors is “on” at any given time. As a result, CMOS devices require less power than devices that use only a single type of transistor.
One difficulty associated with implementing a CMOS pin electronics driver involves regulating the termination impedance of the output pins. Differences in transistor characteristics can affect the termination impedance of an output pin. For example, the transconductance and inherent capacitance of two transistors may vary, resulting in different impedances at an output pin. These differences in impedance can adversely affect the quality of signals transmitted over the output pin.